third_party/tcmalloc/chromium/src/static_vars.h

   1 // Copyright (c) 2008, Google Inc.
   2 // All rights reserved.
   3 //
   4 // Redistribution and use in source and binary forms, with or without
   5 // modification, are permitted provided that the following conditions are
   6 // met:
   7 //
   8 //     * Redistributions of source code must retain the above copyright
   9 // notice, this list of conditions and the following disclaimer.
  10 //     * Redistributions in binary form must reproduce the above
  11 // copyright notice, this list of conditions and the following disclaimer
  12 // in the documentation and/or other materials provided with the
  13 // distribution.
  14 //     * Neither the name of Google Inc. nor the names of its
  15 // contributors may be used to endorse or promote products derived from
  16 // this software without specific prior written permission.
  17 //
  18 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  19 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  20 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  21 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  22 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  23 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  24 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  25 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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  28 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  29
  30 // ---
  31 // Author: Ken Ashcraft <opensource@google.com>
  32 //
  33 // Static variables shared by multiple classes.
  34
  35 #ifndef TCMALLOC_STATIC_VARS_H_
  36 #define TCMALLOC_STATIC_VARS_H_
  37
  38 #include <config.h>
  39 #include "base/spinlock.h"
  40 #include "central_freelist.h"
  41 #include "common.h"
  42 #include "page_heap.h"
  43 #include "page_heap_allocator.h"
  44 #include "span.h"
  45 #include "stack_trace_table.h"
  46
  47 namespace tcmalloc {
  48
  49 class Static {
  50  public:
  51   // Linker initialized, so this lock can be accessed at any time.
  52   static SpinLock* pageheap_lock() { return &pageheap_lock_; }
  53
  54   // Must be called before calling any of the accessors below.
  55   static void InitStaticVars();
  56
  57   // Central cache -- an array of free-lists, one per size-class.
  58   // We have a separate lock per free-list to reduce contention.
  59   static CentralFreeListPadded* central_cache() { return central_cache_; }
  60
  61   static SizeMap* sizemap() { return &sizemap_; }
  62
  63   //////////////////////////////////////////////////////////////////////
  64   // In addition to the explicit initialization comment, the variables below
  65   // must be protected by pageheap_lock.
  66
  67   // Page-level allocator.
  68   static PageHeap* pageheap() { return pageheap_; }
  69
  70   static PageHeapAllocator<Span>* span_allocator() { return &span_allocator_; }
  71
  72   static PageHeapAllocator<StackTrace>* stacktrace_allocator() {
  73     return &stacktrace_allocator_;
  74   }
  75
  76   static StackTrace* growth_stacks() { return growth_stacks_; }
  77   static void set_growth_stacks(StackTrace* s) { growth_stacks_ = s; }
  78
  79   // State kept for sampled allocations (/pprof/heap support)
  80   static Span* sampled_objects() { return &sampled_objects_; }
  81   static PageHeapAllocator<StackTraceTable::Bucket>* bucket_allocator() {
  82     return &bucket_allocator_;
  83   }
  84
  85  private:
  86   static SpinLock pageheap_lock_;
  87
  88   // These static variables require explicit initialization.  We cannot
  89   // count on their constructors to do any initialization because other
  90   // static variables may try to allocate memory before these variables
  91   // can run their constructors.
  92
  93   static SizeMap sizemap_;
  94   static CentralFreeListPadded central_cache_[kNumClasses];
  95   static PageHeapAllocator<Span> span_allocator_;
  96   static PageHeapAllocator<StackTrace> stacktrace_allocator_;
  97   static Span sampled_objects_;
  98   static PageHeapAllocator<StackTraceTable::Bucket> bucket_allocator_;
  99
 100   // Linked list of stack traces recorded every time we allocated memory
 101   // from the system.  Useful for finding allocation sites that cause
 102   // increase in the footprint of the system.  The linked list pointer
 103   // is stored in trace->stack[kMaxStackDepth-1].
 104   static StackTrace* growth_stacks_;
 105
 106   static PageHeap* pageheap_;
 107 };
 108
 109 }  // namespace tcmalloc
 110
 111 #endif  // TCMALLOC_STATIC_VARS_H_